/**
 * ***************************************************************************** Copyright (c) 2000,
 * 2008 IBM Corporation and others. All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: IBM Corporation - initial API and implementation
 * *****************************************************************************
 */
package org.eclipse.ltk.core.refactoring;

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.ltk.core.refactoring.history.IRefactoringHistoryService;
import org.eclipse.ltk.internal.core.refactoring.RefactoringCorePlugin;
import org.eclipse.ltk.internal.core.refactoring.history.RefactoringContributionManager;
import org.eclipse.ltk.internal.core.refactoring.history.RefactoringHistoryService;

/**
 * Central access point to access resources managed by the refactoring core plug-in.
 *
 * <p>Note: this class is not intended to be extended by clients.
 *
 * @since 3.0
 * @noextend This class is not intended to be subclassed by clients.
 */
public class RefactoringCore {

  /**
   * The id of the Refactoring plug-in (value <code>"org.eclipse.ltk.core.refactoring"</code>).
   *
   * @since 3.2
   */
  public static final String ID_PLUGIN = "org.eclipse.ltk.core.refactoring"; // $NON-NLS-1$

  private static IValidationCheckResultQueryFactory fQueryFactory = new DefaultQueryFactory();

  private static class NullQuery implements IValidationCheckResultQuery {
    public boolean proceed(RefactoringStatus status) {
      return true;
    }

    public void stopped(RefactoringStatus status) {
      // do nothing
    }
  }

  private static class DefaultQueryFactory implements IValidationCheckResultQueryFactory {
    public IValidationCheckResultQuery create(IAdaptable context) {
      return new NullQuery();
    }
  }

  private RefactoringCore() {
    // no instance
  }

  /**
   * Returns the singleton undo manager for the refactoring undo stack.
   *
   * @return the refactoring undo manager.
   */
  public static IUndoManager getUndoManager() {
    return RefactoringCorePlugin.getUndoManager();
  }

  /**
   * Returns the singleton refactoring history service.
   *
   * @return the refactoring history service
   * @since 3.2
   */
  public static IRefactoringHistoryService getHistoryService() {
    return RefactoringHistoryService.getInstance();
  }

  /**
   * Returns the refactoring contribution with the specified unique id.
   *
   * @param id the unique id of the contribution
   * @return the refactoring contribution, or <code>null</code> if in contribution is registered
   *     with for this id
   * @since 3.2
   */
  public static RefactoringContribution getRefactoringContribution(String id) {
    return RefactoringContributionManager.getInstance().getRefactoringContribution(id);
  }

  /**
   * When condition checking is performed for a refactoring then the condition check is interpreted
   * as failed if the refactoring status severity return from the condition checking operation is
   * equal or greater than the value returned by this method.
   *
   * @return the condition checking failed severity
   */
  public static int getConditionCheckingFailedSeverity() {
    return RefactoringStatus.WARNING;
  }

  /**
   * Returns the query factory.
   *
   * @return the query factory
   * @since 3.1
   */
  public static IValidationCheckResultQueryFactory getQueryFactory() {
    return fQueryFactory;
  }

  /**
   * An internal method to set the query factory.
   *
   * <p>This method is NOT official API. It is a special method for the refactoring UI plug-in to
   * set a dialog based query factory.
   *
   * @param factory the factory to set or <code>null</code>
   * @since 3.1
   * @noreference This method is not intended to be referenced by clients.
   */
  public static void internalSetQueryFactory(IValidationCheckResultQueryFactory factory) {
    if (factory == null) {
      fQueryFactory = new DefaultQueryFactory();
    } else {
      fQueryFactory = factory;
    }
  }
}
